Steljes ML-50HD Ground connection help?

[vaporize]

Hi all, newbie here, still learning the ropes, and would appreciate a bit of advice!

I have a nifty little Steljes ML50HD, just cracked it open to see if a quick deoxidising of the volume pot would sort out a different problem, but then also noticed the GND screw and an empty GND spot on the PCB.

I presume the ground screw is grounding through the metal chassis, it isn't connected to anything else. Then I wondered if anything is supposed to be connected to the PCB GND? It sits on it's own just behind the phono RCA inputs. The power (DC input) is way across in the corner. Pictures attached.

Thanks for any help!

 

[duncan2]

Without a schematic diagram the other way to tell is use a cheap digital meter to test for continuity between the PCB "earth " and the chassis earth .